My Experiments With Code - Chintan Patel

How to Open winmail.dat Files on iOS (iPhone and iPad)

A week ago, i released my first iOS app to the App Store: Winmail.dat File Viewer Pro. This post is about how I did market research to find what to build as my first iOS app on App Store.

If Microsoft Outlook server is not configured correctly, it can send out emails as “winmail.dat” files instead of the actual email with attachments.

The winmail.dat file is a TNEF-encoded file containing the email body text as a “.rtf” file along with any other attachments if present.

Receiving such files on any platform can be a problem because the recipient is not sure how to open the winmail.dat file to access text and attachments contained within the email. Moreover, most senders will be unaware of the cause of this issue and may need help of their IT department to solve the issue.

Some users on Apple forums are also suggesting that this issue has started occurring more frequently after they updated to iOS 7 but i have not been able to find any such direct correlation.

Microsoft (or Apple) do not seem to be keen on providing a solution to this years-old problem which would allow users to view contents of TNEF-encoded winmail.dat files without using any 3rd party software.

I saw this as a niche iOS app opportunity and just the kind of weekend project which was perfect for me to release as my first iOS app in the App Store after about 20+ apps shipped to various clients over nearly 5 years as a full-time iOS Developer.

This app may not be useful to everyone but it is inevitable for anyone who receives one of these dreaded winmail.dat email attachments on their iPhone or iPad and have no idea what to do with it. Now, by using Winmail.dat File Viewer Pro, you will be able to open winmail.dat attachments on your iOS device with ease. You can also save the attached files to your Dropbox, Google Drive, Photo Gallery or share it with others using email, Facebook, Twitter etc. depending on the file type.

Since this app is already live on the app store since about 7 days, i will be doing another post this weekend sharing sales/downloads data and thoughts about pricing and designing the app.

So there goes the first app of my own in App Store after thousands of hours of client work!